Dual Screen Organic Electroluminescent Display
A dual screen organic electroluminescent display made by encapsulating two organic electroluminescent screens is provided. Every organic electroluminescent display comprises a transparent substrate, an organic electroluminescent unit, and a chip bonding pad. The organic electroluminescent unit is electrically connected to the chip bonding pad, and both the organic electroluminescent unit and the chip bonding pad are located on the same surface of the transparent substrate. The width of a UV encapsulating glue layer, which is located between the organic electroluminescent unit and the chip bonding pad, is between 0.5 to 10 mm.
Latest AU OPTRONICS CORPORATION Patents:
The present application is based on, and claims priority from, Taiwan Application Serial Number 95108215, filed Mar. 10, 2006, the disclosure of which is hereby incorporated by reference herein in its entirety.
BACKGROUND1. Field of Invention
The present invention relates to a dual screen organic electroluminescent display. More particularly, the present invention relates to a dual screen organic electroluminescent display that prevents the spillage of encapsulating glue when encapsulating.
2. Description of Related Art
With the advancement and evolution of electronic devices, the reaction speed, the resolution and the definition of displays have improved, and the function and the display modes are more advanced. One of the examples is the gradual increase in the need for the portable electronic devices equipped with dual displays, such as folded cell phones, PDAs and notebooks. Dual screens do not only stretch out the size of a display and widen the view, but it is also helpful to switch screens and deal with more tasks. For portable electronic devices, the light weights and small sizes are most important. Main stream displays of modern portable electronic devices are twisted-nematic LCDs and thin-film transistor LCDs. However, though the LCDs are already a kind of light and thin plane displays, there is still a long way to go when being applied to dual screen displays.
It is obvious that one cannot obtain a light, thin and small dual screen display if he or she assembles one by simply combining two individual LCDs back to back. The modern display industry are paying close attention to organic electroluminescent light emitting diode (OLED) displays because of their ability to emit light without back light modules, light weights, small sizes, simple structures, robustness and low costs. Therefore dual screen organic electroluminescent displays are becoming important in the development of dual screen displays.
Reference is now made to
For the forgoing reasons, there is a need for a dual screen organic electroluminescent display that is not made by simply assembling two organic electroluminescent screens back to back and avoids the problem of spilling encapsulating glue.
SUMMARYThe present invention is directed to a dual screen organic electroluminescent display that integrates and encapsulates organic electroluminescent diode display units into a dual screen organic electroluminescent display. By means of the integrated encapsulation structure, the weight and the size of the dual screen organic electroluminescent screen can be reduced. Furthermore, the encapsulation process can be accomplished at once, which is helpful to decrease the cost.
The dual screen organic electroluminescent display of the present invention is formed by integrating and encapsulating two bottom-luminescence organic electroluminescent screens together. Each of the two bottom-luminescence organic electroluminescent screens includes a transparent substrate, a plurality of organic electroluminescent units and an insulation layer. The two bottom-luminescence organic electroluminescent screens are staggered in order to expose the chip bonding pads to ensure successful chip bonding. The organic electroluminescent units are formed over a surface of the transparent substrates. The organic electroluminescent unit is a pile of a transparent electrode, an organic electroluminescent layer, and an upper electrode, wherein the transparent electrode and the upper electrode are installed on two different sides of the organic electroluminescent layer respectively in order to utilize the external voltage to emit the light. The transparent substrate is chosen from a category composed of glass substrates and plastic substrates, the upper electrode may be a metal electrode, and the transparent electrode is chosen from a category composed of Indium tin oxide (ITO), Indium zinc oxide (IZO) and a thin metal layer. The organic electroluminescent layer includes a combination of a hole injection layer, a hole conduction layer, an organic electroluminescent material layer, an electron transfer layer, an electron injection layer, and a carrier production layer.
Besides, there is a further insulation layer on the metal electrode, covering the organic electroluminescent unit. The two bottom-luminescence organic electroluminescent screens are encapsulated, the insulation layer-to-the insulation layer, into a dual screen organic electroluminescent display. The dual screen organic electroluminescent display further includes one or more hygroscopic material layers encapsulated between the two transparent substrates.
Comparing the present dual screen organic electroluminescent display to the conventional laminated dual screen organic electroluminescent display, the components such as the cover glass can be saved to reduce the cost. The UV encapsulating glue is utilized for encapsulation. The width of the encapsulating glue coated on the substrate is smaller than the width between the edge of the light emitting area and the edge of the chip bonding pad area. The width of the encapsulating glue is preferably between 0.5 to 10 mm.
The organic electroluminescent screens of the present invention are driven by a passive matrix or an active matrix, or driven in a mode combining a passive matrix and an active matrix. Further, the dual screen organic electroluminescent display of the present invention may be applied in a monochrome display mode, a high color display mode and a true color display mode. The organic electroluminescent display of the present invention also includes the polymer light emitting diode (PLED) display.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, figures, and appended claims.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Please refer to
Besides, there is an insulation layer (not shown) above the metal electrode, covering the organic electroluminescent unit. The two bottom-luminescence organic electroluminescent display panels 300 and 302 are disposed using insulation layers aligned in the insulation layer direction and encapsulated to form the dual organic electroluminsecent display. Afterwards, the two bottom-luminescence organic electroluminescent display panels 300 and 302 are assembled into a dual screen organic electroluminescent display accordingly. The dual screen organic electroluminescent display further includes one or more hygroscopic material layers (not shown) encapsulated between the two transparent substrates in order to absorb water vapor permeated into the organic electroluminescent screens.
Please refer to
Please refer to
According to the preferred embodiment described above, the present invention has the following advantages. The spillage of the encapsulating glue and hence the damage of the components in the light emitting area, the failure of the chip bonding pads, or the incapability of scribing can all be prevented and avoided if the width of the encapsulating glue layer is limited to between 0.5 to 10 mm. Besides, the two organic electroluminescent screens are stuck and encapsulated in a staggered way. Therefore, the chip bonding pads can be directly formed over the transparent substrate, and the chips can be soldered on the transparent substrate directly as well. Accordingly, the complexity of the fabrication process of the dual screen organic electroluminescent display is reduced.
Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should no be limited to the description of the preferred embodiments contained herein.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention covers modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
Claims
1. A dual screen organic electroluminescent display, comprising at least:
- two organic electroluminescent screens, wherein each of the two organic electroluminescent screens comprises: a transparent substrate; an organic electroluminescent unit, located over a surface of the transparent substrate; and a chip bonding pad, located at a side of the organic electroluminescent unit and electrically connected to the organic electroluminescent unit; and
- an encapsulating layer, surrounding the two organic electroluminescent units for encapsulating the two organic electroluminescent screens with the two organic electroluminescent units opposite to each other, and exposing the two chip bonding pads;
- wherein the width of the encapsulating layer, located between the organic electroluminescent unit and the chip bonding pad, lies between 0.5˜10 mm.
2. The dual screen organic electroluminescent display of claim 1, wherein the two organic electroluminescent screens are staggered in order to expose the chip bonding pads.
3. The dual screen organic electroluminescent display of claim 2, wherein the transparent substrate is chosen from a category composed of glass substrates and plastic substrates.
4. The dual screen organic electroluminescent display of claim 3, wherein the organic electroluminescent unit comprises a pile of a transparent electrode, an organic electroluminescent layer, and an upper electrode.
5. The dual screen organic electroluminescent display of claim 4, wherein the transparent electrode is chosen from a category composed of Indium tin oxide (ITO) layers, Indium zinc oxide (IZO) layers and thin metal layers.
6. The dual screen organic electroluminescent display of claim 5, wherein the organic electroluminescent layer comprises a combination of a hole injection layer, a hole conduction layer, an organic electroluminescent material layer, an electron transfer layer, an electron injection layer, and a carrier production layer.
7. The dual screen organic electroluminescent display of claim 6, further comprising an insulation layer covering the organic electroluminescent unit.
8. The dual screen organic electroluminescent display of claim 7, further comprising one or more hygroscopic material layers encapsulated between the two transparent substrates.
9. The dual screen organic electroluminescent display of claim 8, wherein the organic electroluminescent screens are either passive matrix driven or active matrix driven.
Type: Application
Filed: Sep 20, 2006
Publication Date: Sep 13, 2007
Applicant: AU OPTRONICS CORPORATION (Hsinchu)
Inventors: Min-Ling Hung (Kanding Township), Chun-Yi Chiu (Taoyuan City)
Application Number: 11/533,433
International Classification: H01J 1/62 (20060101); H01J 63/04 (20060101);